1. Field of the Invention
The present invention relates to a heating apparatus for a liquefied gas fuel supply system, for heating liquefied gas fuel when the fuel is vaporized to be supplied to an internal-combustion engine.
2. Description of the Related Art
As well known, an internal-combustion engine, which is provided in, for example, an automobile using a liquefied gas fuel such as liquefied petroleum gas (LPG) is designed to vaporize in a vaporizer the fuel stored under a high pressure and to use the vaporized fuel for combustion. The vaporizer is cooled by latent heat of vaporization of the fuel. When the vaporizer is excessively cooled, the fuel undergoes insufficient vaporization, which has adverse influence on fuel injection control, etc.
Conventionally, in order to prevent such an excessive cooling, JP 2003-328859 A discloses a system for heating fuel in which a heating apparatus introduces engine cooling water into a vaporizer, and is provided with an electric heater in the vaporizer to heat the fuel by means of both heat of the engine cooling water heated in the engine and heat generated from the electric heater.